I think that's what he means. There are two costs to this: one, the financial cost of a legal name change and two, the psychological cost to the child of being called one thing for 10 months then something different after that.

On the other hand... what happens to a travel reservation made under a name, when the name is legally changed to something else before travel? Surely NW would be obligated to update the reservation without charge? I'm thinking of all the people out there who change their names following a divorce or separation, etc. This isn't an enitrely unusual situation.